Fig. 2

A map displaying the provincial distribution of 10,665 undergraduates was drawn using Supermap iDesktop 8C (2017) and then converted into Microsoft Word format. Excluding Taiwan, Hong Kong, and Macao, there are 31 provinces in mainland China. The exact number in the map indicated that the 10,665 participants were unevenly distributed across 30 provinces (except for Tibet with white highlighted), and were mainly (7200) recruited from Hubei province